ABSTRACT
The world is made up of physical and mental facts. On the one hand there are solids, liquids and gases, plants, trees and the bodies of animals, the stars and planets and their movements, the winds and clouds, and so on through the list of physical things and their movements. On the other hand are the thoughts and feelings of men and of other animals; ideas, opinions, memories, hopes, fears, pleasures, pains, smells, tastes, and so on through the list of states of mind. Physics, chemistry, astronomy, botany, zoology, geology and the other physical sciences deal with the former group of facts. Psychology, the science of mental facts or of mind, deals with the latter. Human psychology deals with the thoughts and feelings of human beings and seeks to explain the facts of intellect, character and personal life. How do you remember where you were a year ago? Why do we attend to certain sights and sounds and neglect others? What is the difference between an intelligent pupil and an idiot? What decides how large one shall judge an object to be? What happens when a student reasons out a problem in geometry? Such are the questions which the science of psychology tries to answer.
